There is a limit on simultaneous FTP connections via the web. You can bypass that restriction by using a direct DOS FTP connection in XP/Vista (mget, lcd and that sort of thing through the anonymous account). Other GUI FTP clients may work as well with a direct connection.

It is mirrored at Strategy Informer, we're working on getting more mirrors up. Our FTP server is basically maxed out with people downloading it, so folks are getting through but it's definitely overloaded.